Income Taxes (Schedule Of Components Of Income From Continuing Operations Before Income Taxes And Income Tax Expense (Benefit)) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income (loss) before income taxes	$ 61.9	$ 91.3	$ 43.3	$ 5.9	$ 100.5	$ 57.0	$ 69.1	$ 47.3	$ 202.4	$ 273.9	$ 240.1
Income tax expense (benefit)
Federal - Current									15.6	18.4	39.2
Federal - Deferred									21.7	31.0	(50.7)
State - Current and deferred									10.3	10.9	6.3
Total									$ 47.6	$ 60.3	$ (5.2)